| Testing the RewindButton class. | |
| On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE". | |
| PASS rewindButton.element.localName is "button" | |
| PASS rewindButton.element.classList.contains("rewind") is true | |
| PASS rewindButton.iconName is Icons.Rewind | |
| PASS rewindButton.image.element.style.webkitMaskImage.includes("macOS/Rewind.svg") became true | |
| PASS successfullyParsed is true | |
| TEST COMPLETE | |